The present invention relates to a foldable bicycle frame and a bicycle comprising such a foldable bicycle frame, the foldable bicycle frame comprising a seat tube for accommodating a seat post, an upper tube, a head tube, a lower tube, two chain stays and two seat stays, wherein a first releasable locking mechanism is provided in order to connect, in an unfolded state of the bicycle frame, the seat post, the seat tube, the upper tube and the seat stays in a rigid and detachable manner to each other and to fix the position to each other.